Method of and apparatus for making socketed screws



June 9, 1942.

w. A. PURTEL L METHOD OF AND APPARATUS FOR-MAKING SOGKETED SCREWS:

Fiied May 26, 1939 Figure 4;

Patented June 9,

METHOD OF AND FOR SOCKETED SCREWS PAeur other William A. Pun-tell, West, Hartford, com, as-

signor to The Holo-Krome Screw Corporation, a corporation of Connecticut Application May 26, 1939, Serial in. 275.9%

29 Claims.

My invention relates to methods of and appafl ratus for making socketed screws. I

It has among its objects to provide an improved method for making such screws whereby it is made possible markedly to improve the conformation of the socket andto produce improved binding and guiding surfaces therein adapted to cooperate in an improved manner with'a screw driver. A further object of my invention is to provide such an improved method whereby it is made possible to produce a larger and more readily entered targetthan heretofore possible while avoiding severe displacement of metal during the formation of the socketand in such manner as to produce a stronger socket wall. A further object of my invention is to provide such an improved method wherein the wall of the target is first formed and improved flutes are thereafter formed in the periphery of the wall of the target in such manner as not only to facilitate the formation of the socket, but also to enable new and advantageous movements of the metal relative to the punch. A further object of my invention is to provide improved apparatus adapted to be used in carrying out my improved method, and, more particularly, such apparatus adapted to be used in a header in such manner as to enable the screws to be readily, quickly and-inexpensively produced. These and other objects and advantages of my improvements will, however, hereinafter appear.

In the accompanying drawing, Ihave shown for purposes of illustration one form of apparatus which may be be used in carrying out my improvements.

In the drawing: c

Figure 1 is a central sectional view or the preliminary punching mechanism ready to operate on an upset blank;

Fig.2 is a like view but showing the mechanism after preliminary punching: Fig. 3 is an enlarged plan view of the blank after preliminary punching:

Fig. 4 is a view similar to Figure 2 but showing the flute forming punch in vertical section in the preliminarilypunched blank;

Fig. 4a is aside elevation of the working end of the flute forming punch;

Fig; 5 is an enlarged section on Iine'H of Fig; 6 is an enlarged section on line of Figure 4;

Fig. 7 isa section on line l-Fbf Figure 5; Fig. 8 is an enlarged pleted socket;

planview of the com- Fig. 9 is' an enlarged partial side elevation of the finished screw, the socket being shown in section on line t-Q of Figure 8," and Fig. 10 is a reduced sectional view corresponding to Figure 5 but showing a modified iormof ribbed punch in a modified form of socket.

In Figures 1 to 7, I have shown my improvements applied to use in producing a screw of the 10 pending application Serial No. 275,903, filed May 26, 1939; the screw being formed from a wire blank and having the targetinitially formed in a preliminary punching operation and the fluted portions subsequently formed in the target wall, all in animprovedmanner, as hereinafter more fully described. 1

The blank I is preferably in the form of a section 01 wire or bar stock, of suitable length. This blank is first upset in an upsetting die aperture 0 2 in a stationary die .8, the inner. end of the shank then extending into an axial aperture 5 and being supported therein upon'a suitable knockout pin-t. The upset end to oi the blank projects and beyond the latter aperture so that this upset end "is adapted to have a preliminary punching formed therein by a movable die 6 having on its working end an axial conical punch l surrounded by an annular shoulder d.

' end to of the blank l is formed into a conical head portion 9 conforming to the shape of the die aperture 2 and filling out the latter, while being punched verticallyby the punch I. More particularly, the conicalpunch 1 forms an axial conical aperture ill, while the shoulder d on the punch forms a fiat annular surface II on the head a surrounding the aperture to. Here it will' be noted that the aperture idls of such dimen- 40 sions that its outer end produces a large axially located, round, mouth, or so-ealled target, portions of the outer end of which, as will-hereinafter appear, are thus completely formed in this preliminary punching operation.

After the blank has been formed into the shape shown in Figures 2 and 3, the punch I is withdrawn and moved out of alignment with the blank, and an improved punch l2 is utilizedto complete the formation of the socket. As shown punch and'provided with concave end walls My and converging side walls 15 connected'at their points of minimum cross section with a body construction described and claimed in my cothrough the aperture 2, herein of conical form,

When the punch 6 moves downward, the upsete completely formed in the' two operations ward the extremity of the tool. Although its cross section at its outer end is of less diameter than the mouth of the aperture l formed by the conical punch 1, it will be observed that the extremity of this body somewhat enlarges the inner end of the apertur III, as shown in Figure 7. It will also be observed that the ribs l3 extend radially beyond this body portion It in Attention is further directed to the fact that the preliminary aperture, which is very conveniently formed after upsetting, not only makes 1 easier the operation of the punch l2, but also forms the target wall. Further, the preliminary formation of this target and the subsequent forming of the fluted portions, makes possible a such manner that as the punch l2 moves downward into the aperture to, the extremities of the ribs form fluted. portions l1 conforming in shape to the extremities of the ribs and having convex end walls l8 conforming to the concave surfaces l4, and converging side walls l9 conforming to the side walls on the extremities of the ribs i3. Further, it will be particularly noted that, due to the large aperture l0 and the space provided between the wall thereof and the body portion 16 of the punch H, the metal in the walls of the aperture is free to flow out of the path of the ribs It as the latter move downward to form the fluted portions l'l, while the intermediate abutment portions 20 at the upper ends of the aperture l0 retain their' original con formation. Further, it will'be observed that the lower ends of theseportions 20 are convexly shaped by the extremities of the portion It. on

punchv I! as shown at 20a, while the convex end walls It are similarly formed by concave surfaces It on the ribs IS in such manner as to provide surfaces lBa at their lower ends corresponding to the surfaces 20a. It will also be noted that very uniform distribution of the displaced metal and aminimum of severe displacement, in such manner as to produce a strong socket. Moreover, due to the provision of the preliminary punching, it is made possible for the metal displaced by the ribs onthe punch I! to move freely out of the path of these ribs, despite the converging walls ii on these ribs, and without causing binding or undue wear on the punch.

In Figure 10, I have illustrated a punch modified cross section which may be used if desired to produce a modified form of screw of the construction described and claimed in my copending application Serial No. 275,902, filed May 26, 1939. Here it will be noted that the tapered ribsof the punch have diverging convex side walls 2| intersecting at their inner ends in a 'concave line 22 at their Junction with the tapered body of the punch, while the screw has corresponding concave intersecting side walls on its surfaces 2011, I81: and I9 approach the axis of the socket'on arcs at increasingly acute angles to said axis, in such manner as to produce at the inner ends of the socket a plurality of series of radially and laterally disposed binding surfaces disposed around the entire socket and adapted effectively to wed e and hold a reciprocably inserted turning tool as described in my application mentioned.

As a result of my improvements, it will be observed that convex end walls It including the in-.

creasinglyacutelyangled portions l8a are readily provided in the flutedportions, and that like walls or surfaces 20a are formed on the abutments20 in such manner as, with surfaces l9 and i811, to form binding, gripping or wedging surfaces disposed at varying sharp angles to the axis of the socket and thus adapted effectively to retain the screw on a driver and inserted in the socket. Further, the side walls of the fluted portions are so formed as to provide a large contact area and to enable them to cooperate in this retaining function while minimizing camming and enabling the metarto be uniformly displaced as necessary in producing a strong. head and eliminating objectionable wear on the punch. Herein, the screw shown figures 8 and 9111s require no further shaping while the fluted pore tionsjil are formed. Also, these portions ii are formed at spaced points around the periphery of the preliminary aperture It, in such manner as to provide a strong socket adapted to receive corresponding turning portions on a screw driver and cooperate therewith without mutilation or breakage of the socket walls.

fluted portions intersecting on convex lines, the

end walls of the slots and the side walls thereof forming binding surfaces generally corresponding to the surfaces It and II heretofore de--- scribed. Here,- it will be understood that corresponding but narrower convex and concave end walls 23, 231: are provided on the screw 24 and punch ribs 25, respectively, and corresponding to the convex surfaces It and II as heretofore described, so that like improved convex binding, wedging or gripping surfaces. not shown but corresponding to'the surfaces "a, and disposed at varying sharp angles to the axis, are formed'at the inner ends of the slots or fluted portions, these conv x surfaces also preferably extending upward an diverging outward to the mouth of the socket to provide guiding surfaces as heretofore described. Thus, in thisconstruction also the portions 23a, 2| and 22 cooperate to produce at the inner end of the socket a plurality of series of turning tool wedging portions disposed around the entire socket. In this construction, both the conical body portion l6 on the punch and the large preliminary sg cket HI heretofore described are omitted, although a smaller preliminary punching may be used if desired. y

g It will be understood that either form of my improved punch may'also be utilized asa screw driver if desired, although preferably the bottom extremity of the punch is slightly out back when so used. Also when used as a screw driver the concave end surfaces on the ribs may be shortened if desired so that there is no contact with the upper portions of the convex end walls of the fluted portions or slots in the screw, it being found that my improved g ipping, binding or wedging effect at the inner ends-of the slots is such as to make this possible.

While I have in thisapplication specifically described certain embodiments which my invention may assume in practice, it will be understood that these forms have been shown for purposes of illustration, and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

- arcades r 1 The methodof making socketed. screws which consists in, punching the mouth portion mouthed conformation. Y 3.The method of making socketed screws which consists in, punching a mouth portion on the socket while preliminarily punching the remainder-thereof, and convexly grooving said mouth portion at radially spaced points while punching the remainder of the socket.

4. The method of making socketed screws which consists in, punching a mouth portion on the socket while preliminarily punching the remaindeithere )f, and punching said remainder while convexly grooving at radially spaced points both said mouth portion andsaid remainder.

5. The. method of making socketed screws which consists in, punching a bell mouthed target aperture in one end of a blank while, preliminarily punching the remainder of the socket, and punching convex radial slots in the walls of said aperture extending down tothe bot- 6. The method of making socketed screwswhich consists in,-punching a bell mouthed portion, of. the socket while preliminarily punching the remainder thereof, and punching said remainder while radially slotting both the latter and said bell mouthed portion and substantially maintaining the conformation of the portions of said bell mouthed portion between the slots.;

7.'The method of making socketed screws -which consists in, punching a blank to form a" mouth portion of the socket and a smaller preliminarily punched portion below said mouth portion, and-punching said smaller portion toen- 11. In an apparatus for making socketed screws, punching mechanism for forming thev mouth of a socket while preliminarily punching the remainder; of thesocket, and mechanism for punching the remainder of the socket and radially slotting said mouth portion while maintaining the general conformation of the mouth portion between the slots.

- 1-2. In an apparatus for making socketed screws, mechanism for punching a bell mouthed mouth portion in the upset end of a blank while preliminarily punching the socket' below said portion, and mechanism for punching said preliminarily punched portion while radially slottingsaid bell mouthed portion and the remainder of the socket.

13. In an apparatus for making socketed screws, mechanism for punching a bell mouthed mouth portion in the upset end of a blank while preliminarily punching the blank below said portion, and mechanism for punching saidpreli-minarily punched portion while radially slotting said bell mouthed portion and the remainder of the socket and forming turning tool binding surfaces in. the bottom of the socket.

14. Apparatus for making socketed screws including a punch having tapered radially located ribs thereon having concave end walls diverging from the axis of the punch at the larger ends of said ribs and disposed in substantial parallelism with the axis of end thereof.

15. A tool havingradially located longitudinally extending rib portions on its working end tapering toward its extremity and also having concave end wallson the lower extremities ;of

i said rib portions having their extremities disposed at increasingly acute angles to the axis of said tool.

16. A tool having radially located longitudinally extending rib portions on its working end tapering toward its extremity and also having concave end walls on the lower extremities of said rib portions and vertically concave portions be-l tween said rib portions.

17. Atool having radially located longitudi-- nally extending rib-like portions on its working 9. In-an apparatus for making socketed screws,

curvature of the inner portion of the preliminary recess while leaving at least a substantial portion of the wallof the mouth portion of the same general contour.

end disposed in intersecting planes around the.

latter and tapering toward its extremity and also having concave end walls on said rib portions having their extremitiesdisposed at increasingly acute angles to the axis of said tool.

18. A .tool having radially located longitudinallyextending rib portions on;-its working end tapering toward its extremity and also having vertically concave portions on the end walls of said rib portions comprising elongated binding portions leading toward said extremity and disposed at increasingly-acute angles to the axis of the tool.

19. A tool having radially located longitudinally extending rib-like portions on its working end disposed in intersecting planes around the latter and tapering toward the extremity of the tool and having end and side walls on said ribs, thelower extremities of said end walls being disposed at increasingly sharp angles to the axis of the tool and said side walls having their lower extremities approaching a vertical plane passing between the same.

20. A tool having radially located longitudinally extending rib-like portions on its working end disposed in intersectingplanes around the latter and tapering toward the extremity of the tool and having end and side walls on said ribs,

said punch at the smaller I the lower extremities of said end ,walls being disposed at increasingly sharp angles to the axis of the tool and said side walls having their lower extremities approaching a vertical plane passing between the same, and the body of said tool having between adjacent side walls concave portions having their lower extremities disposed at increasingly acute angles to the axis of the tool.

' verging toward the axis of the tool, laterally convex vertically tapered portions on the body of the tool connecting adjacent side walls, and concave end walls on the lower extremities of saidrib portions.

23. A tool having radially located longitudinally extending rib portions on its working end tapering toward its extremity and also having side walls on said rib portions diverging toward the body of said tool and intersecting on contapering toward the extremity or. the tool and having vertically tapered laterally convex side walls on said rib portions diverging toward the body of said tool, and vertically concaveportions on' said rib portions between said convex side walls and having their extremities disposed at increasingly acute angles to the axis of the tool.

26, A tool having radially located longitudinally extendlng rib-like portions on its working end disposed in intersecting planes around the latter and tapering toward the extremity of the tool and also having concave portions between said rib portions and on the end walls of the latter, having their extremities disposed at increasingly acute angles to the axis of the tool.

27. A tool having radially located longitudinally extending rib-like portions on its working end disposed in intersecting planes around the latter and tapering toward the extremity of the tool and also having vertically concave portions on the end walls of said rib portions having their extremities disposed at increasingly acute angles cave lines, and concave end walls on the lower extremities of said rib portions having their extremities disposed at increasingly acute angles to the axis of said tool. p

24. A tool having radially located longitudinally extending rib portions on its working end tapering toward the extremity or the tool and having vertically tapered laterally convex side walls on said rib portions diverging toward the body of said tool.

25. A tool having radially located longitudinally extending rib portions on. its working end to the axis of the tool.

- 28. A tool having radially located longitudinally extending rib-like portions on its working end disposed in intersecting planes around the latter and tapering toward the extremity ofthe tool and also having vertically concave portions on the end walls of said rib portions and vertically concave lines on the body of the tool formed by intersecting side walls of adjacent rib v portions and having the extremities of said concave portions and lines disposed at increasingly acute angles to the axis of the tool.

29. A tool having radially locatedilongitudt nally extending rib portions on its working end tapering toward its extremity and also having tapered side walls on said rib portions diverging toward the body of said tool, and concave end walls on the lower extremities of said rib portions, said side walls also being laterally convex WILLIAM A. PUR'I'ELL. 

